Imidazopyridines as cyclin dependent kinase inhibitors

ABSTRACT

In its many embodiments, the present invention provides a novel class of imidazo[1,2-a]pyridine compounds as inhibitors of cyclin dependent kinases, methods of preparing such compounds, pharmaceutical compositions containing one or more such compounds, methods of preparing pharmaceutical formulations comprising one or more such compounds, and methods of treatment, prevention, inhibition, or amelioration of one or more diseases associated with the CDKs using such compounds or pharmaceutical compositions.

RELATED APPLICATIONS

This application is a divisional of application U.S. Ser. No.10/664,338, filed Sep. 17, 2003, now allowed and herein incorporated byreference, which in turn claims benefit under 35 USC 119(e) toprovisional application U.S. Ser. No. 60/412,063, filed Sep. 19, 2002.

FIELD OF THE INVENTION

The present invention relates to imidazo[1,2-a]pyridine compounds usefulas protein kinase inhibitors (such as for example, the inhibitors of thecyclin-dependent kinases, mitogen-activated protein kinase (MAPK/ERK),glycogen synthase kinase 3 (GSK3beta) and the like), pharmaceuticalcompositions containing the compounds, and methods of treatment usingthe compounds and compositions to treat diseases such as, for example,cancer, inflammation, arthritis, viral diseases, neurodegenerativediseases such as Alzheimer's disease, cardiovascular diseases, andfungal diseases. This application claims the benefit of priority fromU.S. provisional patent application Ser. No. 60/412,063, filed Sep. 19,2002.

BACKGROUND OF THE INVENTION

Protein kinase inhibitors include kinases such as, for example, theinhibitors of the cyclin-dependent kinases (CDKs), mitogen activatedprotein kinase (MAPK/ERK), glycogen synthase kinase 3 (GSK3beta), andthe like. The cyclin-dependent kinases are serine/threonine proteinkinases, which are the driving force behind the cell cycle and cellproliferation. Individual CDK's, such as, CDK1, CDK2, CDK3, CDK4, CDK5,CDK6 and CDK7, CDK8 and the like, perform distinct roles in cell cycleprogression and can be classified as either G1, S, or G2M phase enzymes.Uncontrolled proliferation is a hallmark of cancer cells, andmisregulation of CDK function occurs with high frequency in manyimportant solid tumors. CDK2 and CDK4 are of particular interest becausetheir activities are frequently misregulated in a wide variety of humancancers. CDK2 activity is required for progression through G1 to the Sphase of the cell cycle, and CDK2 is one of the key components of the G1checkpoint. Checkpoints serve to maintain the proper sequence of cellcycle events and allow the cell to respond to insults or toproliferative signals, while the loss of proper checkpoint control incancer cells contributes to tumorgenesis. The CDK2 pathway influencestumorgenesis at the level of tumor suppressor function (e.g. p52, RB,and p27) and oncogene activation (cyclin E). Many reports havedemonstrated that both the coactivator, cyclin E, and the inhibitor,p27, of CDK2 are either over- or underexpressed, respectively, inbreast, colon, nonsmall cell lung, gastric, prostate, bladder,non-Hodgkin's lymphoma, ovarian, and other cancers. Their alteredexpression has been shown to correlate with increased CDK2 activitylevels and poor overall survival. This observation makes CDK2 and itsregulatory pathways compelling targets for the development years, anumber of adenosine 5′-triphosphate (ATP) competitive small organicmolecules as well as peptides have been reported in the literature asCDK inhibitors for the potential treatment of cancers. U.S. Pat. No.6,413,974, col. 1, line 23-col. 15, line 10 offers a good description ofthe various CDKs and their relationship to various types of cancer.

CDK inhibitors are known. For example, flavopiridol (Formula I) is anonselective CDK inhibitor that is currently undergoing human clinicaltrials, A. M. Sanderowicz et al, J. Clin. Oncol. (1998) 16, 2986-2999.

Other known inhibitors of the CDKs include, for example, olomoucine (J.Vesely et al, Eur. J. Biochem., (1994) 224, 771-786) and roscovitine (I.Meijer et al, Eur. J. Biochem., (1997) 243, 527-536). U.S. Pat. No.6,107,305 describes certain pyrazolo[3,4-b]pyridine compounds as CDKinhibitors. An illustrative compound from the '305 patent has theFormula II:

K. S. Kim et al, J. Med. Chem. 45 (2002) 3905-3927 and WO 02/10162disclose certain aminothiazole compounds as CDK inhibitors.

Pyrazolopyrimidines are known. For Example, WO92/18504, WO02/50079,WO95/35298, WO02/40485, EP94304104.6, EP0628559 (equivalent to U.S. Pat.Nos. 5,602,136, 5,602,137 and 5,571,813), U.S. Pat. No. 6,383,790, Chem.Pharm. Bull., (1999) 47 928, J. Med. Chem., (1977) 20, 296, J. Med.Chem., (1976) 19 517 and Chem. Pharm. Bull., (1962) 10 620 disclosevarious pyrazolopyrimidines.

There is a need for new compounds, formulations, treatments andtherapies to treat diseases and disorders associated with CDKs. It is,therefore, an object of this invention to provide compounds useful inthe treatment or prevention or amelioration of such diseases anddisorders.

SUMMARY OF THE INVENTION

In its many embodiments, the present invention provides a novel class ofimidazo[1,2-a]pyridine compounds as inhibitors of cyclin dependentkinases, methods of preparing such compounds, pharmaceuticalcompositions comprising one or more such compounds, methods of preparingpharmaceutical formulations comprising one or more such compounds, andmethods of treatment, prevention, inhibition or amelioration of one ormore diseases associated with the CDKs using such compounds orpharmaceutical compositions.

In one aspect, the present application discloses a compound, orpharmaceutically acceptable salts or solvates of said compound, saidcompound having the general structure shown in Formula III:

wherein:R is selected from the group consisting of alkyl, aryl, heteroaryl,heteroarylalkyl, heterocyclyl, heterocyclylalkyl, arylalkyl, cycloalkyl,—NR⁶R⁷, —C(O)R⁷, —C(O)OR⁶, —C(O)NR⁶R⁷ and —S(O₂)R⁷, wherein each of saidalkyl, aryl, heteroaryl, heteroarylalkyl, heterocyclyl,heterocyclylalkyl, cycloalkyl and arylalkyl can be unsubstituted oroptionally independently substituted with one or more moieties which canbe the same or different, each moiety being independently selected fromthe group consisting of halogen, alkyl, cycloalkyl, CF₃, CN, —OCF₃,—OR⁶, —C(O)R⁷, —NR⁶R⁷, —C(O)OR⁶, —C(O)NR⁵R⁶, —SR⁶, —S(O₂)R⁷,—S(O₂)NR⁵R⁶, —N(R⁵)S(O₂)R⁷, —N(R⁵)C(O)R⁷ and —N(R⁵)C(O)NR⁵R⁶ and NO₂;

R² is selected from the group consisting of H, R⁹, alkyl, aryl,arylalkyl, heteroaryl, heteroarylalkyl, heterocyclyl, heterocyclylalkyl,alkenyl, alkynyl, cycloalkyl, —CF₃, —C(O)R⁷, alkyl substituted with 1-6R⁹ groups which groups can be the same or different with each R⁹ beingindependently selected,

wherein each of said aryl, heteroaryl, arylalkyl and heterocyclyl can beunsubstituted or optionally independently substituted with one or moremoieties which can be the same or different, each moiety beingindependently selected from the group consisting of halogen, alkyl,cycloalkyl, CF₃, CN, —OCF₃, —OR⁶, —C(O)R⁷, —NR⁶R⁷, —C(O)OR⁶, —C(O)NR⁵R⁶,—SR⁶, —S(O₂)R⁷, —S(O₂)NR⁵R⁶, —N(R⁵)S(O₂)R⁷, —N(R⁵)C(O)R⁷ and—N(R⁵)C(O)NR⁵R⁶;

R³ is selected from the group consisting of H, halogen, —NR⁵R⁶, CF₃,alkyl, cycloalkyl, aryl, heteroaryl, heteroarylalkyl, heterocyclyl,heterocyclylalkyl, alkynyl, alkenyl, —(CHR⁵)_(n)-aryl,—(CHR⁵)_(n)-heteroaryl, —(CHR⁵)_(n)—OR⁶, —S(O₂)R⁶, —C(O)R⁶, —S(O₂)NR⁵R⁶,—C(O)OR⁶, —C(O)NR⁵R⁶, —CH(aryl)₂, —(CH₂)_(m)—NR⁸,

wherein each of said aryl, alkyl, arylalkyl, cycloalkyl, heteroaryl,heteroarylalkyl, heterocyclyl and heterocyclylalkyl for R³ and theheterocyclyl moieties whose structures are shown immediately above forR³ can be unsubstituted or optionally independently substituted with oneor more moieties which moieties can be the same or different, eachmoiety being independently selected from the group consisting ofhalogen, alkyl, aryl, cycloalkyl, CF₃, CN, —OCF₃, —OR⁵, —C(R⁴R⁵)_(n)OR⁵,—NR⁵R⁶, —C(R⁴R⁵)_(n)NR⁵R⁶, —C(O₂)R⁵, —C(O)R⁵, —C(O)NR⁵R⁶, —SR⁶,—S(O₂)R⁶, —S(O₂)NR⁵R⁶, —N(R⁵)S(O₂)R⁷, —N(R⁵)C(O)R⁷ and —N(R⁵)C(O)NR⁵R⁶;

R⁴ is selected from the group consisting of H, halogen, CF₃, alkyl,cycloalkyl, aryl, heteroaryl, heteroarylalkyl, heterocyclyl,heterocyclylalkyl, alkynyl, alkenyl, —(CHR⁵)_(n)-aryl,—(CHR⁵)_(n)-heteroaryl, —(CHR⁵)_(n)—OR⁶, —S(O₂)R⁵, —C(O)R⁶, —S(O₂)NR⁵R⁶,—C(O)OR⁶, —C(O)NR⁵R⁶, cycloalkyl, —CH(aryl)₂, —(CH₂)_(m)—NR⁸, and

wherein each of said aryl, alkyl, cycloalkyl, heteroaryl,heteroarylalkyl, heterocyclyl and heterocyclylalkyl can be unsubstitutedor optionally substituted with one or more moieties which can be thesame or different, each moiety being independently selected from thegroup consisting of halogen, alkyl, aryl, cycloalkyl, CF₃, CN, —OCF₃,—OR⁵, —NR⁵R⁶, —C(O₂)R⁵, —C(O)NR⁵R⁶, —SR⁶ and —S(O₂)R⁶;

R⁵ is H, alkyl or aryl;

R⁶ is selected from the group consisting of H, alkyl, aryl, heteroaryl,arylalkyl, cycloalkyl, heteroarylalkyl, heterocyclyl andheterocyclylalkyl, wherein each of said alkyl, aryl, heteroaryl,arylalkyl, cycloalkyl, heteroarylalkyl, heterocyclyl andheterocyclylalkyl can be unsubstituted or optionally independentlysubstituted with one or more moieties which can be the same ordifferent, each moiety being independently selected from the groupconsisting of halogen, alkyl, aryl, cycloalkyl, heterocyclylalkyl, CF₃,OCF₃, CN, —OR⁵, —NR⁵R¹⁰, —N(R⁵)Boc, —C(R⁴R⁵)OR⁵, —C(O)R⁶, —C(O)OR⁵,—C(O)NR⁵R¹⁰, —SO₃H, —SR¹⁰, —S(O₂)R⁷, —S(O₂)NR⁵R¹⁰, —N(R⁵)S(O₂)R⁷,—N(R⁵)C(O)R⁷ and —N(R⁵)C(O)NR⁵R¹⁰;

R¹⁰ is selected from the group consisting of H, alkyl, aryl, arylalkyl,cycloalkyl, heterocyclyl, heterocyclylalkyl, heteroaryl, andheteroarylalkyl, wherein each of said alkyl, aryl, arylalkyl,cycloalkyl, heterocyclyl, heterocyclylalkyl, heteroaryl, andheteroarylalkyl can be unsubstituted or optionally substituted with oneor more moieties which can be the same or different, each moiety beingindependently selected from the group consisting of halogen, alkyl,aryl, cycloalkyl, heterocyclylalkyl, CF₃, OCF₃, CN, —OR⁵, —NR⁴R⁵,—N(R⁵)Boc, —(CR⁴R⁵)_(n)OR⁵, —C(O₂)R⁵, —C(O)NR⁴R⁵, —C(O)R⁵, —SO₃H, —SR⁵,—S(O₂)R⁷, —S(O₂)NR⁴R⁵, —N(R⁵)S(O₂)R⁷, —N(R⁵)C(O)R⁷ and —N(R⁵)C(O)NR⁴R⁵;

-   -   or optionally (i) R⁵ and R¹⁰ in the moiety —NR⁵R¹⁰, or (ii) R⁵        and R⁶ in the moiety —NR⁵R⁶, may be joined together to form a        cycloalkyl or heterocyclyl moiety, with each of said cycloalkyl        or heterocyclyl moiety being unsubstituted or optionally        independently being substituted with one or more R⁹ groups;

R⁷ is selected from the group consisting of alkyl, cycloalkyl, aryl,heteroaryl, arylalkyl and heteroarylalkyl wherein each of said alkyl,cycloalkyl, heteroarylalkyl, aryl, heteroaryl and arylalkyl can beunsubstituted or optionally independently substituted with one or moremoieties which can be the same or different, each moiety beingindependently selected from the group consisting of halogen, alkyl,aryl, cycloalkyl, CF₃, OCF₃, CN, —OR⁵, —NR⁵R¹⁰, —CH₂OR⁵, —C(O₂)R⁵,—C(O)NR⁵R¹⁰, —C(O)R⁵, —SR¹⁰, —S(O₂)R¹⁰, —S(O₂)NR⁵R¹⁰, —N(R⁵)S(O₂)R¹⁰,—N(R⁵)C(O)R¹⁰ and —N(R⁵)C(O)NR⁵R¹⁰;

R⁸ is selected from the group consisting of R⁶, —C(O)NR⁵R¹⁰,—S(O₂)NR⁵R¹⁰, —C(O)R⁷, —C(O)OR⁶ and —S(O₂)R⁷;

R⁹ is selected from the group consisting of halogen, CN, NR⁵R¹⁰,—C(O)OR⁶, —C(O)NR⁵R¹⁰, —OR⁶, —C(O)R⁷, —SR⁶, —S(O₂)R⁷, —S(O₂)NR⁵R¹⁰,—N(R⁵)S(O₂)R⁷, —N(R⁵)C(O)R⁷ and —N(R⁵)C(O)NR⁵R¹⁰;

R¹¹ is H, alkyl or aryl;

m is 0 to 4; and

n is 1-4.

The compounds of Formula III can be useful as protein kinase inhibitorsand can be useful in the treatment and prevention of proliferativediseases, for example, cancer, inflammation and arthritis. They may alsobe useful in the treatment of neurodegenerative diseases suchAlzheimer's disease, cardiovascular diseases, viral diseases and fungaldiseases.

DETAILED DESCRIPTION

In one embodiment, the present invention disclosesimidazo[1,2-a]pyridine compounds which are represented by structuralFormula III, or a pharmaceutically acceptable salt or solvate thereof,wherein the various moieties are as described above.

In another embodiment, R is selected from the group consisting of aryl,arylalkyl, heteroaryl, heteroarylalkyl, alkyl, —S(O₂)R⁷, and —C(O)R⁷,wherein each of said aryl, arylalkyl, heteroaryl, heteroarylalkyl andalkyl can be unsubstituted or optionally independently substituted withone or more moieties which can be the same or different, each moietybeing independently selected from the group consisting of halogen,alkyl, CF₃, CN, —OCF₃, —NR⁶R⁷, —N(R⁵)C(O)R⁷, and —OR⁶.

In another embodiment, R² is selected from the group consisting ofhalogen, alkyl, aryl, heteroaryl, alkenyl and —C(O)R⁷, wherein each ofsaid alkyl, aryl and heteroaryl can be unsubstituted or optionallyindependently substituted with one or more moieties which can be thesame or different, each moiety being independently selected from thegroup consisting of halogen, alkyl, CF₃, CN, —OCF₃, and —OR⁶.

In another embodiment, R³ is selected from the group consisting of H,aryl, heteroaryl, —(CHR⁵)_(n)-aryl, —(CHR⁵)_(n)-heteroaryl,—(CHR⁵)_(n)—OR⁶, —C(O)R⁶, cycloalkyl, —NR⁵R⁶, —CH(aryl)₂,

wherein each of said aryl, cycloalkyl and heteroaryl and theheterocyclyl structures shown immediately above for R³ can besubstituted or optionally independently substituted with one or moremoieties which can be the same or different, each moiety beingindependently selected from the group consisting of halogen, CF₃, OCF₃,alkyl, CN, aryl, —C(O)R⁵, —C(O₂)R⁵, —S(O₂)R⁶, —C(═NH)—NH₂, —C(═CN)—NH₂,hydroxyalkyl, alkoxycarbonyl, —SR⁶, and OR⁵, with the proviso that nocarbon adjacent to a nitrogen atom on a heterocyclyl ring carries a —OR⁵moiety.

In another embodiment of a compound of Formula III, R⁴ is selected fromthe group consisting of H, alkyl, aryl, heteroaryl, —(CHR⁵)_(n)-aryl,—(CHR⁵)_(n)-heteroaryl, —(CHR⁵)_(n)—OR, —C(O)R⁶, cycloalkyl, —CH(aryl)₂and

wherein each of said aryl and heteroaryl can be unsubstituted oroptionally substituted with one or more moieties which can be the sameor different, each moiety being independently selected from the groupconsisting of halogen, alkyl, aryl, CF₃, CN, —C(O₂)R⁵ and —S(O₂)R⁶.

In another embodiment, R⁵ is H, aryl or lower alkyl.

In another embodiment of a compound of Formula III, R¹¹ is H or loweralkyl.

In another embodiment, m is 0 to 2.

In another embodiment, n is 1 to 3.

In an additional embodiment, R is selected from the group consisting ofphenyl, benzyl, benzoyl, phenylsulfonyl, thienyl, thienylalkyl,thienylcarbonyl, thienylsulfonyl, furyl, furylalkyl, furylcarbonyl,furylsulfonyl, pyridyl, pyridylalkyl, pyridylcarbonyl, pyridylsulfonyl,pyrrolyl, pyrrolylalkyl, pyrrolylcarbonyl, pyrrolylsulfonyl, oxazolyl,oxazolylalkyl, oxazolylcarbonyl, oxazolylsulfonyl, thiazolyl,thiazolylalkyl, thiazolylcarbonyl, thiazolylsulfonyl, pyrazinyl,pyrazinylalkyl, pyrazinylcarbonyl, pyrazinylsulfonyl, pyridazinyl,pyridazinylalkyl, pyridazinylcarbonyl, pyridazinylsulfonyl, pyrimidinyl,pyrimidinylalkyl, pyrimidinylcarbonyl, pyrimidinylsulfonyl, —S(O₂)CH₃,and —C(O)CH₃, as well as their applicable N-oxides, wherein each of saidphenyl (including the phenyl of the benzyl), thienyl, furyl, pyridyl,pyrrolyl, oxazolyl, thiazolyl, pyrazinyl, pyridazinyl and pyrimidinylcan be unsubstituted or optionally independently substituted with one ormore moieties which can be the same or different, each moiety beingindependently selected from the group consisting of Cl, Br, I, loweralkyl, CF₃, CN, —C(O)OR⁶, —NR⁶R⁷, —N(R⁵)C(O)R⁷, —OCF₃, and —OH.

In an additional embodiment, R is unsubstituted phenyl, unsubstitutedpyridyl, benzyl whose phenyl can be unsubstituted or optionallysubstituted with one or more moieties selected from the group consistingof F, Cl, Br, CN, CF₃, —NH₂, and —N(H)C(O)CH₃, benzoyl whose phenyl canbe unsubstituted or optionally substituted with one or more moietiesselected from the group consisting of F, Cl, Br, CN, CF₃, —NH₂, and—N(H)C(O)CH₃, phenylsulfonyl whose phenyl can be unsubstituted oroptionally substituted with one or more moieties selected from the groupconsisting of F, Cl, Br, CN, —NH₂, —N(H)C(O)CH₃ and CF₃, pyridylmethylwhose pyridyl can be unsubstituted or optionally substituted with one ormore moieties selected from the group consisting of F, Cl, Br, CN, CF₃,—NH₂, and —N(H)C(O)CH₃, pyridylcarbonyl whose pyridyl can beunsubstituted or optionally substituted with one or more moietiesselected from the group consisting of F, Cl, Br, CN, CF₃, —NH₂, and—N(H)C(O)CH₃, pyridylsulfonyl whose pyridyl can be unsubstituted oroptionally substituted with one or more moieties selected from the groupconsisting of F, Cl, Br, CN, —NH₂, —N(H)C(O)CH₃ and CF₃, pyrimidylmethylwhose pyrimidylmethyl can be unsubstituted or optionally substitutedwith one or more moieties selected from the group consisting of F, Cl,Br, CN, —NH₂, —N(H)C(O)CH₃ and CF₃, pyrimidylcarbonyl whose pyrimidylcan be unsubstituted or optionally substituted with one or more moietiesselected from the group consisting of F, Cl, Br, CN, —NH₂, —N(H)C(O)CH₃and CF₃, or pyrimidylsulfonyl whose pyrimidyl can be unsubstituted oroptionally substituted with one or more moieties selected from the groupconsisting of F, Cl, Br, CN, —NH₂, —N(H)C(O)CH₃ and CF₃.

In an additional embodiment, R² is H, F, Cl, Br, I, hydroxyalkyl,alkoxyalkyl, or lower alkyl.

In an additional embodiment, R³ is H, alkyl, aryl, —NR⁵R⁶,

wherein said alkyl and aryl and the heterocyclyl moieties shownimmediately above for R³ can be unsubstituted or optionallyindependently substituted with one or more moieties (in addition to anyR⁸) which can be the same or different, each moiety being independentlyselected from the group consisting of F, Cl, Br, CF₃, lower alkyl,hydroxyalkyl, alkoxy, —S(O₂)R⁶, and CN.

In an additional embodiment, R⁴ is H, alkyl or aryl, wherein said alkylor aryl can be unsubstituted or optionally independently substitutedwith one or more moieties which can be the same or different, eachmoiety being independently selected from the group consisting of F, Cl,Br, CF₃, lower alkyl, hydroxyalkyl, alkoxy, —S(O₂)R⁶, and CN.

In an additional embodiment, R⁵ is H.

In an additional embodiment, R¹¹ is H.

In an additional embodiment, m is 0.

In an additional embodiment, n is 1 or 2.

An inventive group of compounds is shown in Table 1.

TABLE 1

As used above, and throughout this disclosure, the following terms,unless otherwise indicated, shall be understood to have the followingmeanings:

“Patient” includes both human and animals.

“Mammal” means humans and other mammalian animals.

“Alkyl” means an aliphatic hydrocarbon group which may be straight orbranched and comprising about 1 to about 20 carbon atoms in the chain.Preferred alkyl groups contain about 1 to about 12 carbon atoms in thechain. More preferred alkyl groups contain about 1 to about 6 carbonatoms in the chain. Branched means that one or more lower alkyl groupssuch as methyl, ethyl or propyl, are attached to a linear alkyl chain.“Lower alkyl” means a group having about 1 to about 6 carbon atoms inthe chain which may be straight or branched. The term “substitutedalkyl” means that the alkyl group may be substituted by one or moresubstituents which may be the same or different, each substituent beingindependently selected from the group consisting of halo, alkyl, aryl,cycloalkyl, cyano, hydroxy, alkoxy, alkylthio, amino, —NH(alkyl),—NH(cycloalkyl), —N(alkyl)₂, carboxy and —C(O)O-alkyl. Non-limitingexamples of suitable alkyl groups include methyl, ethyl, n-propyl,isopropyl and t-butyl.

“Alkynyl” means an aliphatic hydrocarbon group containing at least onecarbon-carbon triple bond and which may be straight or branched andcomprising about 2 to about 15 carbon atoms in the chain. Preferredalkynyl groups have about 2 to about 12 carbon atoms in the chain; andmore preferably about 2 to about 4 carbon atoms in the chain. Branchedmeans that one or more lower alkyl groups such as methyl, ethyl orpropyl, are attached to a linear alkynyl chain. “Lower alkynyl” meansabout 2 to about 6 carbon atoms in the chain which may be straight orbranched. Non-limiting examples of suitable alkynyl groups includeethynyl, propynyl, 2-butynyl and 3-methylbutynyl. The term “substitutedalkynyl” means that the alkynyl group may be substituted by one or moresubstituents which may be the same or different, each substituent beingindependently selected from the group consisting of alkyl, aryl andcycloalkyl.

“Aryl” means an aromatic monocyclic or multicyclic ring systemcomprising about 6 to about 14 carbon atoms, preferably about 6 to about10 carbon atoms. The aryl group can be optionally substituted with oneor more “ring system substituents” which may be the same or different,and are as defined herein. Non-limiting examples of suitable aryl groupsinclude phenyl and naphthyl.

“Heteroaryl” means an aromatic monocyclic or multicyclic ring systemcomprising about 5 to about 14 ring atoms, preferably about 5 to about10 ring atoms, in which one or more of the ring atoms is an elementother than carbon, for example nitrogen, oxygen or sulfur, alone or incombination. Preferred heteroaryls contain about 5 to about 6 ringatoms. The “heteroaryl” can be optionally substituted by one or more“ring system substituents” which may be the same or different, and areas defined herein. The prefix aza, oxa or thia before the heteroarylroot name means that at least a nitrogen, oxygen or sulfur atomrespectively, is present as a ring atom. A nitrogen atom of a heteroarylcan be optionally oxidized to the corresponding N-oxide. Non-limitingexamples of suitable heteroaryls include pyridyl, pyrazinyl, furanyl,thienyl, pyrimidinyl, pyridone (including N-substituted pyridones),isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazolyl, furazanyl,pyrrolyl, pyrazolyl, triazolyl, 1,2,4-thiadiazolyl, pyrazinyl,pyridazinyl, quinoxalinyl, phthalazinyl, oxindolyl,imidazo[1,2-a]pyridinyl, imidazo[2,1-b]thiazolyl, benzofurazanyl,indolyl, azaindolyl, benzimidazolyl, benzothienyl, quinolinyl,imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidyl,pyrrolopyridyl, imidazopyridyl, isoquinolinyl, benzoazaindolyl,1,2,4-triazinyl, benzothiazolyl and the like. The term “heteroaryl” alsorefers to partially saturated heteroaryl moieties such as, for example,tetrahydroisoquinolyl, tetrahydroquinolyl and the like.

“Aralkyl” or “arylalkyl” means an aryl-alkyl- group in which the aryland alkyl are as previously described. Preferred aralkyls comprise alower alkyl group. Non-limiting examples of suitable aralkyl groupsinclude benzyl, 2-phenethyl and naphthalenylmethyl. The bond to theparent moiety is through the alkyl.

“Alkylaryl” means an alkyl-aryl- group in which the alkyl and aryl areas previously described. Preferred alkylaryls comprise a lower alkylgroup. Non-limiting example of a suitable alkylaryl group is tolyl. Thebond to the parent moiety is through the aryl.

“Cycloalkyl” means a non-aromatic mono- or multicyclic ring systemcomprising about 3 to about 10 carbon atoms, preferably about 5 to about10 carbon atoms. Preferred cycloalkyl rings contain about 5 to about 7ring atoms. The cycloalkyl can be optionally substituted with one ormore “ring system substituents” which may be the same or different, andare as defined above. Non-limiting examples of suitable monocycliccycloalkyls include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyland the like. Non-limiting examples of suitable multicyclic cycloalkylsinclude 1-decalinyl, norbornyl, adamantyl and the like, as well aspartially saturated species such as, for example, indanyl,tetrahydronaphthyl and the like.

“Halogen” means fluorine, chlorine, bromine, or iodine. Preferred arefluorine, chlorine and bromine.

“Ring system substituent” means a substituent attached to an aromatic ornon-aromatic ring system which, for example, replaces an availablehydrogen on the ring system. Ring system substituents may be the same ordifferent, each being independently selected from the group consistingof alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, alkylaryl,heteroaralkyl, heteroarylalkenyl, heteroarylalkynyl, alkylheteroaryl,hydroxy, hydroxyalkyl, alkoxy, aryloxy, aralkoxy, acyl, aroyl, halo,nitro, cyano, carboxy, alkoxycarbonyl, aryloxycarbonyl,aralkoxycarbonyl, alkylsulfonyl, arylsulfonyl, heteroarylsulfonyl,alkylthio, arylthio, heteroarylthio, aralkylthio, heteroaralkylthio,cycloalkyl, heterocyclyl, —C(═N—CN)—NH₂, —C(═NH)—NH₂, —C(═NH)—NH(alkyl),Y₁Y₂N—, Y₁Y₂N-alkyl-, Y₁Y₂NC(O)—, Y₁Y₂NSO₂— and —SO₂NY₁Y₂, wherein Y₁and Y₂ can be the same or different and are independently selected fromthe group consisting of hydrogen, alkyl, aryl, cycloalkyl, and aralkyl.“Ring system substituent” may also mean a single moiety whichsimultaneously replaces two available hydrogens on two adjacent carbonatoms (one H on each carbon) on a ring system. Examples of such moietyare methylene dioxy, ethylenedioxy, —C(CH₃)₂— and the like which formmoieties such as, for example:

“Heterocyclyl” means a non-aromatic saturated monocyclic or multicyclicring system comprising about 3 to about 10 ring atoms, preferably about5 to about 10 ring atoms, in which one or more of the atoms in the ringsystem is an element other than carbon, for example nitrogen, oxygen orsulfur, alone or in combination. There are no adjacent oxygen and/orsulfur atoms present in the ring system. Preferred heterocyclyls containabout 5 to about 6 ring atoms. The prefix aza, oxa or thia before theheterocyclyl root name means that at least a nitrogen, oxygen or sulfuratom respectively is present as a ring atom. Any —NH in a heterocyclylring may exist protected such as, for example, as an —N(Boc), —N(CBz),—N(Tos) group and the like; such protections are also considered part ofthis invention. The heterocyclyl can be optionally substituted by one ormore “ring system substituents” which may be the same or different, andare as defined herein. The nitrogen or sulfur atom of the heterocyclylcan be optionally oxidized to the corresponding N-oxide, S-oxide orS,S-dioxide. Non-limiting examples of suitable monocyclic heterocyclylrings include piperidyl, pyrrolidinyl, piperazinyl, morpholinyl,thiomorpholinyl, thiazolidinyl, 1,4-dioxanyl, tetrahydrofuranyl,tetrahydrothiophenyl, lactam, lactone, and the like.

It should be noted that in hetero-atom containing ring systems of thisinvention, there are no hydroxyl groups on carbon atoms adjacent to a N,O or S, as well as there are no N or S groups on carbon adjacent toanother heteroatom. Thus, for example, in the ring:

there is no —OH attached directly to carbons marked 2 and 5.

It should also be noted that tautomeric forms such as, for example, themoieties:

are considered equivalent in certain embodiments of this invention.

“Alkynylalkyl” means an alkynyl-alkyl- group in which the alkynyl andalkyl are as previously described. Preferred alkynylalkyls contain alower alkynyl and a lower alkyl group. The bond to the parent moiety isthrough the alkyl. Non-limiting examples of suitable alkynylalkyl groupsinclude propargylmethyl.

“Heteroaralkyl” means a heteroaryl-alkyl- group in which the heteroaryland alkyl are as previously described. Preferred heteroaralkyls containa lower alkyl group. Non-limiting examples of suitable aralkyl groupsinclude pyridylmethyl, and quinolin-3-ylmethyl. The bond to the parentmoiety is through the alkyl.

“Hydroxyalkyl” means a HO-alkyl- group in which alkyl is as previouslydefined. Preferred hydroxyalkyls contain lower alkyl. Non-limitingexamples of suitable hydroxyalkyl groups include hydroxymethyl and2-hydroxyethyl.

“Acyl” means an H—C(O)—, alkyl-C(O)— or cycloalkyl-C(O)—, group in whichthe various groups are as previously described. The bond to the parentmoiety is through the carbonyl. Preferred acyls contain a lower alkyl.Non-limiting examples of suitable acyl groups include formyl, acetyl andpropanoyl.

“Aroyl” means an aryl-C(O)— group in which the aryl group is aspreviously described. The bond to the parent moiety is through thecarbonyl. Non-limiting examples of suitable groups include benzoyl and1-naphthoyl.

“Alkoxy” means an alkyl-O— group in which the alkyl group is aspreviously described. Non-limiting examples of suitable alkoxy groupsinclude methoxy, ethoxy, n-propoxy, isopropoxy and n-butoxy. The bond tothe parent moiety is through the ether oxygen.

“Aryloxy” means an aryl-O— group in which the aryl group is aspreviously described. Non-limiting examples of suitable aryloxy groupsinclude phenoxy and naphthoxy. The bond to the parent moiety is throughthe ether oxygen.

“Aralkyloxy” means an aralkyl-O— group in which the aralkyl group is aspreviously described. Non-limiting examples of suitable aralkyloxygroups include benzyloxy and 1- or 2-naphthalenemethoxy. The bond to theparent moiety is through the ether oxygen.

“Alkylthio” means an alkyl-S— group in which the alkyl group is aspreviously described. Non-limiting examples of suitable alkylthio groupsinclude methylthio and ethylthio. The bond to the parent moiety isthrough the sulfur.

“Arylthio” means an aryl-S— group in which the aryl group is aspreviously described. Non-limiting examples of suitable arylthio groupsinclude phenylthio and naphthylthio. The bond to the parent moiety isthrough the sulfur.

“Aralkylthio” means an aralkyl-S— group in which the aralkyl group is aspreviously described. Non-limiting example of a suitable aralkylthiogroup is benzylthio. The bond to the parent moiety is through thesulfur.

“Alkoxycarbonyl” means an alkyl-O—CO— group. Non-limiting examples ofsuitable alkoxycarbonyl groups include methoxycarbonyl andethoxycarbonyl. The bond to the parent moiety is through the carbonyl.

“Aryloxycarbonyl” means an aryl-O—C(O)— group. Non-limiting examples ofsuitable aryloxycarbonyl groups include phenoxycarbonyl andnaphthoxycarbonyl. The bond to the parent moiety is through thecarbonyl.

“Aralkoxycarbonyl” means an aralkyl-O—C(O)— group. Non-limiting exampleof a suitable aralkoxycarbonyl group is benzyloxycarbonyl. The bond tothe parent moiety is through the carbonyl.

“Alkylsulfonyl” means an alkyl-S(O₂)— group. Preferred groups are thosein which the alkyl group is lower alkyl. The bond to the parent moietyis through the sulfonyl.

“Arylsulfonyl” means an aryl-S(O₂)— group. The bond to the parent moietyis through the sulfonyl.

The term “substituted” means that one or more hydrogens on thedesignated atom is replaced with a selection from the indicated group,provided that the designated atom's normal valency under the existingcircumstances is not exceeded, and that the substitution results in astable compound. Combinations of substituents and/or variables arepermissible only if such combinations result in stable compounds. By“stable compound’ or “stable structure” is meant a compound that issufficiently robust to survive isolation to a useful degree of purityfrom a reaction mixture, and formulation into an efficacious therapeuticagent.

The term “optionally substituted” means optional substitution with thespecified groups, radicals or moieties.

The term “isolated” or “in isolated form” for a compound refers to thephysical state of said compound after being isolated from a syntheticprocess or natural source or combination thereof. The term “purified” or“in purified form” for a compound refers to the physical state of saidcompound after being obtained from a purification process or processesdescribed herein or well known to the skilled artisan, in sufficientpurity to be characterizable by standard analytical techniques describedherein or well known to the skilled artisan.

It should also be noted that any heteroatom with unsatisfied valences inthe text, schemes, examples and Tables herein is assumed to have thehydrogen atom(s) to satisfy the valences.

When a functional group in a compound is termed “protected”, this meansthat the group is in modified form to preclude undesired side reactionsat the protected site when the compound is subjected to a reaction.Suitable protecting groups will be recognized by those with ordinaryskill in the art as well as by reference to standard textbooks such as,for example, T. W. Greene et al, Protective Groups in organic Synthesis(1991), Wiley, New York.

When any variable (e.g., aryl, heterocycle, R², etc.) occurs more thanone time in any constituent or in Formula III, its definition on eachoccurrence is independent of its definition at every other occurrence.

As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients in the specified amounts,as well as any product which results, directly or indirectly, fromcombination of the specified ingredients in the specified amounts.

Prodrugs and solvates of the compounds of the invention are alsocontemplated herein. The term “prodrug”, as employed herein, denotes acompound that is a drug precursor which, upon administration to asubject, undergoes chemical conversion by metabolic or chemicalprocesses to yield a compound of Formula III or a salt and/or solvatethereof. A discussion of prodrugs is provided in T. Higuchi and V.Stella, Pro-drugs as Novel Delivery Systems (1987) 14 of the A.C.S.Symposium Series, and in Bioreversible Carriers in Drug Design, (1987)Edward B. Roche, ed., American Pharmaceutical Association and PergamonPress, both of which are incorporated herein by reference thereto.

“Solvate” means a physical association of a compound of this inventionwith one or more solvent molecules. This physical association involvesvarying degrees of ionic and covalent bonding, including hydrogenbonding. In certain instances the solvate will be capable of isolation,for example when one or more solvent molecules are incorporated in thecrystal lattice of the crystalline solid. “Solvate” encompasses bothsolution-phase and isolatable solvates. Non-limiting examples ofsuitable solvates include ethanolates, methanolates, and the like.“Hydrate” is a solvate wherein the solvent molecule is H₂O.

“Effective amount” or “therapeutically effective amount” is meant todescribe an amount of compound or a composition of the present inventioneffective in inhibiting the CDK(s) and thus producing the desiredtherapeutic, ameliorative, inhibitory or preventative effect.

The compounds of Formula III can form salts which are also within thescope of this invention. Reference to a compound of Formula III hereinis understood to include reference to salts thereof, unless otherwiseindicated. The term “salt(s)”, as employed herein, denotes acidic saltsformed with inorganic and/or organic acids, as well as basic saltsformed with inorganic and/or organic bases. In addition, when a compoundof Formula III contains both a basic moiety, such as, but not limited toa pyridine or imidazole, and an acidic moiety, such as, but not limitedto a carboxylic acid, zwitterions (“inner salts”) may be formed and areincluded within the term “salt(s)” as used herein. Pharmaceuticallyacceptable (i.e., non-toxic, physiologically acceptable) salts arepreferred, although other salts are also useful. Salts of the compoundsof the Formula III may be formed, for example, by reacting a compound ofFormula III respectively with an amount of acid or base, such as anequivalent amount, in a medium such as one in which the saltprecipitates or in an aqueous medium followed by lyophilization.

Exemplary acid addition salts include acetates, ascorbates, benzoates,benzenesulfonates, bisulfates, borates, butyrates, citrates,camphorates, camphorsulfonates, fumarates, hydrochlorides,hydrobromides, hydroiodides, lactates, maleates, methanesulfonates,naphthalenesulfonates, nitrates, oxalates, phosphates, propionates,salicylates, succinates, sulfates, tartarates, thiocyanates,toluenesulfonates (also known as tosylates,) and the like. Additionally,acids which are generally considered suitable for the formation ofpharmaceutically useful salts from basic pharmaceutical compounds arediscussed, for example, by S. Berge et al, Journal of PharmaceuticalSciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics(1986) 33 201-217; Anderson et al, The Practice of Medicinal Chemistry(1996), Academic Press, New York; and in The Orange Book (Food & DrugAdministration, Washington, D.C. on their website). These disclosuresare incorporated herein by reference thereto.

Exemplary basic salts include ammonium salts, alkali metal salts such assodium, lithium, and potassium salts, alkaline earth metal salts such ascalcium and magnesium salts, salts with organic bases (for example,organic amines) such as dicyclohexylamines, t-butyl amines, and saltswith amino acids such as arginine, lysine and the like. Basicnitrogen-containing groups may be quarternized with agents such as loweralkyl halides (e.g. methyl, ethyl, and butyl chlorides, bromides andiodides), dialkyl sulfates (e.g. dimethyl, diethyl, and dibutylsulfates), long chain halides (e.g. decyl, lauryl, and stearylchlorides, bromides and iodides), aralkyl halides (e.g. benzyl andphenethyl bromides), and others.

All such acid salts and base salts are intended to be pharmaceuticallyacceptable salts within the scope of the invention and all acid and basesalts are considered equivalent to the free forms of the correspondingcompounds for purposes of the invention.

Compounds of Formula III, and salts, solvates and prodrugs thereof, mayexist in their tautomeric form (for example, as an amide or iminoether). All such tautomeric forms are contemplated herein as part of thepresent invention.

All stereoisomers (for example, geometric isomers, optical isomers andthe like) of the present compounds (including those of the salts,solvates and prodrugs of the compounds as well as the salts and solvatesof the prodrugs), such as those which may exist due to asymmetriccarbons on various substituents, including enantiomeric forms (which mayexist even in the absence of asymmetric carbons), rotameric forms,atropisomers, and diastereomeric forms, are contemplated within thescope of this invention, as are positional isomers (such as, forexample, 4-pyridyl and 3-pyridyl). Individual stereoisomers of thecompounds of the invention may, for example, be substantially free ofother isomers, or may be admixed, for example, as racemates or with allother, or other selected, stereoisomers. The chiral centers of thepresent invention can have the S or R configuration as defined by theIUPAC 1974 Recommendations. The use of the terms “salt”, “solvate”“prodrug” and the like, is intended to equally apply to the salt,solvate and prod rug of enantiomers, stereoisomers, rotamers, tautomers,positional isomers, racemates or prodrugs of the inventive compounds.

The compounds according to the invention have pharmacologicalproperties; in particular, the compounds of Formula III can beinhibitors of protein kinases such as, for example, the inhibitors ofthe cyclin-dependent kinases, mitogen-activated protein kinase(MAPK/ERK), glycogen synthase kinase 3 (GSK3beta) and the like. Thecyclin dependent kinases (CDKs) include, for example, CDC2 (CDK1), CDK2,CDK4, CDK5, CDK6, CDK7 and CDK8. The novel compounds of Formula III areexpected to be useful in the therapy of proliferative diseases such ascancer, autoimmune diseases, viral diseases, fungal diseases,neurological/neurodegenerative disorders, arthritis, inflammation,anti-proliferative (e.g., ocular retinopathy), neuronal, alopecia andcardiovascular disease. Many of these diseases and disorders are listedin U.S. Pat. No. 6,413,974 cited earlier, the disclosure of which isincorporated herein.

More specifically, the compounds of Formula III can be useful in thetreatment of a variety of cancers, including (but not limited to) thefollowing: carcinoma, including that of the bladder, breast, colon,kidney, liver, lung, including small cell lung cancer, esophagus, gallbladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin,including squamous cell carcinoma;

hematopoietic tumors of lymphoid lineage, including leukemia, acutelymphocytic leukemia, acute lymphoblastic leukemia, B-cell lymphoma,T-cell lymphoma, Hodgkins lymphoma, non-Hodgkins lymphoma, hairy celllymphoma and Burkett's lymphoma;

hematopoietic tumors of myeloid lineage, including acute and chronicmyelogenous leukemias, myelodysplastic syndrome and promyelocyticleukemia;

tumors of mesenchymal origin, including fibrosarcoma andrhabdomyosarcoma;

tumors of the central and peripheral nervous system, includingastrocytoma, neuroblastoma, glioma and schwannomas; and

other tumors, including melanoma, seminoma, teratocarcinoma,osteosarcoma, xenoderoma pigmentosum, keratoctanthoma, thyroidfollicular cancer and Kaposi's sarcoma.

Due to the key role of CDKs in the regulation of cellular proliferationin general, inhibitors could act as reversible cytostatic agents whichmay be useful in the treatment of any disease process which featuresabnormal cellular proliferation, e.g., benign prostate hyperplasia,familial adenomatosis polyposis, neuro-fibromatosis, atherosclerosis,pulmonary fibrosis, arthritis, psoriasis, glomerulonephritis, restenosisfollowing angioplasty or vascular surgery, hypertrophic scar formation,inflammatory bowel disease, transplantation rejection, endotoxic shock,and fungal infections.

Compounds of Formula III may also be useful in the treatment ofAlzheimer's disease, as suggested by the recent finding that CDK5 isinvolved in the phosphorylation of tau protein (J. Biochem, (1995) 117,741-749).

Compounds of Formula III may induce or inhibit apoptosis. The apoptoticresponse is aberrant in a variety of human diseases. Compounds ofFormula III, as modulators of apoptosis, will be useful in the treatmentof cancer (including but not limited to those types mentionedhereinabove), viral infections (including but not limited to herpevirus,poxvirus, Epstein-Barr virus, Sindbis virus and adenovirus), preventionof AIDS development in HIV-infected individuals, autoimmune diseases(including but not limited to systemic lupus, erythematosus, autoimmunemediated glomerulonephritis, rheumatoid arthritis, psoriasis,inflammatory bowel disease, and autoimmune diabetes mellitus),neurodegenerative disorders (including but not limited to Alzheimer'sdisease, AIDS-related dementia, Parkinson's disease, amyotrophic lateralsclerosis, retinitis pigmentosa, spinal muscular atrophy and cerebellardegeneration), myelodysplastic syndromes, aplastic anemia, ischemicinjury associated with myocardial infarctions, stroke and reperfusioninjury, arrhythmia, atherosclerosis, toxin-induced or alcohol relatedliver diseases, hematological diseases (including but not limited tochronic anemia and aplastic anemia), degenerative diseases of themusculoskeletal system (including but not limited to osteoporosis andarthritis) aspirin-sensitive rhinosinusitis, cystic fibrosis, multiplesclerosis, kidney diseases and cancer pain.

Compounds of Formula III, as inhibitors of the CDKs, can modulate thelevel of cellular RNA and DNA synthesis. These agents would therefore beuseful in the treatment of viral infections (including but not limitedto HIV, human papilloma virus, herpesvirus, poxvirus, Epstein-Barrvirus, Sindbis virus and adenovirus).

Compounds of Formula III may also be useful in the chemoprevention ofcancer. Chemoprevention is defined as inhibiting the development ofinvasive cancer by either blocking the initiating mutagenic event or byblocking the progression of pre-malignant cells that have alreadysuffered an insult or inhibiting tumor relapse.

Compounds of Formula III may also be useful in inhibiting tumorangiogenesis and metastasis.

Compounds of Formula III may also act as inhibitors of other proteinkinases, e.g., protein kinase C, her2, raf 1, MEK1, MAP kinase, EGFreceptor, PDGF receptor, IGF receptor, Pl3 kinase, wee1 kinase, Src, Abland thus be effective in the treatment of diseases associated with otherprotein kinases.

Another aspect of this invention is a method of treating a mammal (e.g.,human) having a disease or condition associated with the CDKs byadministering a therapeutically effective amount of at least onecompound of Formula III, or a pharmaceutically acceptable salt orsolvate of said compound to the mammal.

A preferred dosage is about 0.001 to 500 mg/kg of body weight/day of thecompound of Formula III. An especially preferred dosage is about 0.01 to25 mg/kg of body weight/day of a compound of Formula III, or apharmaceutically acceptable salt or solvate of said compound.

The compounds of this invention may also be useful in combination(administered together or sequentially) with one or more of anti-cancertreatments such as radiation therapy, and/or one or more anti-canceragents selected from the group consisting of cytostatic agents,cytotoxic agents (such as for example, but not limited to, DNAinteractive agents (such as cisplatin or doxorubicin)); taxanes (e.g.taxotere, taxol); topoisomerase II inhibitors (such as etoposide);topoisomerase I inhibitors (such as irinotecan (or CPT-11), camptostar,or topotecan); tubulin interacting agents (such as paclitaxel, docetaxelor the epothilones); hormonal agents (such as tamoxifen); thymidilatesynthase inhibitors (such as 5-fluorouracil); anti-metabolites (such asmethoxtrexate); alkylating agents (such as temozolomide (TEMODAR™ fromSchering-Plough Corporation, Kenilworth, N.J.), cyclophosphamide);Farnesyl protein transferase inhibitors (such as, SARASAR™(4-[2-[4-[(11R)-3,10-dibromo-8-chloro-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-yl-]-1-piperidinyl]-2-oxoehtyl]-1-piperidinecarboxamide,or SCH 66336 from Schering-Plough Corporation, Kenilworth, N.J.),tipifarnib (Zarnestra® or R115777 from Janssen Pharmaceuticals),L778,123 (a farnesyl protein transferase inhibitor from Merck & Company,Whitehouse Station, N.J.), BMS 214662 (a farnesyl protein transferaseinhibitor from Bristol-Myers Squibb Pharmaceuticals, Princeton, N.J.);signal transduction inhibitors (such as, Iressa (from Astra ZenecaPharmaceuticals, England), Tarceva (EGFR kinase inhibitors), antibodiesto EGFR (e.g., C225), GLEEVEC® (C-abl kinase inhibitor from NovartisPharmaceuticals, East Hanover, N.J.); interferons such as, for example,intron (from Schering-Plough Corporation), Peg-Intron (fromSchering-Plough Corporation); hormonal therapy combinations; aromatasecombinations; ara-C, adriamycin, cytoxan, and gemcitabine.

Other anti-cancer (also known as anti-neoplastic) agents include but arenot limited to Uracil mustard, Chlormethine, Ifosfamide, Melphalan,Chlorambucil, Pipobroman, Triethylenemelamine,Triethylenethiophosphoramine, Busulfan, Carmustine, Lomustine,Streptozocin, Dacarbazine, Floxuridine, Cytarabine, 6-Mercaptopurine,6-Thioguanine, Fludarabine phosphate, oxaliplatin, leucovirin,oxaliplatin (ELOXATIN™ from Sanofi-Synthelabo Pharmaeuticals, France),Pentostatine, Vinblastine, Vincristine, Vindesine, Bleomycin,Dactinomycin, Daunorubicin, Doxorubicin, Epirubicin, Idarubicin,Mithramycin, Deoxycoformycin, Mitomycin-C, L-Asparaginase, Teniposide17α-Ethinylestradiol, Diethylstilbestrol, Testosterone, Prednisone,Fluoxymesterone, Dromostanolone propionate, Testolactone,Megestrolacetate, Methylprednisolone, Methyltestosterone, Prednisolone,Triamcinolone, Chlorotrianisene, Hydroxyprogesterone, Aminoglutethimide,Estramustine, Medroxyprogesteroneacetate, Leuprolide, Flutamide,Toremifene, goserelin, Cisplatin, Carboplatin, Hydroxyurea, Amsacrine,Procarbazine, Mitotane, Mitoxantrone, Levamisole, Navelbene,Anastrazole, Letrazole, Capecitabine, Reloxafine, Droloxafine, orHexamethylmelamine.

If formulated as a fixed dose, such combination products employ thecompounds of this invention within the dosage range described herein andthe other pharmaceutically active agent or treatment within its dosagerange. For example, the CDC2 inhibitor olomucine has been found to actsynergistically with known cytotoxic agents in inducing apoptosis (J.Cell Sci., (1995) 108, 2897. Compounds of Formula III may also beadministered sequentially with known anticancer or cytotoxic agents whena combination formulation is inappropriate. The invention is not limitedin the sequence of administration; compounds of Formula III may beadministered either prior to or after administration of the knownanticancer or cytotoxic agent. For example, the cytotoxic activity ofthe cyclin-dependent kinase inhibitor flavopiridol is affected by thesequence of administration with anticancer agents. Cancer Research,(1997) 57, 3375. Such techniques are within the skills of personsskilled in the art as well as attending physicians.

Accordingly, in an aspect, this invention includes combinationscomprising an amount of at least one compound of Formula III, or apharmaceutically acceptable salt or solvate thereof, and an amount ofone or more anti-cancer treatments and anti-cancer agents listed abovewherein the amounts of the compounds/treatments result in desiredtherapeutic effect.

The pharmacological properties of the compounds of this invention may beconfirmed by a number of pharmacological assays. The exemplifiedpharmacological assays which are described later have been carried outwith the compounds according to the invention and their salts.

This invention is also directed to pharmaceutical compositions whichcomprise at least one compound of Formula III, or a pharmaceuticallyacceptable salt or solvate of said compound and at least onepharmaceutically acceptable carrier.

For preparing pharmaceutical compositions from the compounds describedby this invention, inert, pharmaceutically acceptable carriers can beeither solid or liquid. Solid form preparations include powders,tablets, dispersible granules, capsules, cachets and suppositories. Thepowders and tablets may be comprised of from about 5 to about 95 percentactive ingredient. Suitable solid carriers are known in the art, e.g.,magnesium carbonate, magnesium stearate, talc, sugar or lactose.Tablets, powders, cachets and capsules can be used as solid dosage formssuitable for oral administration. Examples of pharmaceuticallyacceptable carriers and methods of manufacture for various compositionsmay be found in A. Gennaro (ed.), Remington's Pharmaceutical Sciences,18^(th) Edition, (1990), Mack Publishing Co., Easton, Pa.

Liquid form preparations include solutions, suspensions and emulsions.As an example may be mentioned water or water-propylene glycol solutionsfor parenteral injection or addition of sweeteners and opacifiers fororal solutions, suspensions and emulsions. Liquid form preparations mayalso include solutions for intranasal administration.

Aerosol preparations suitable for inhalation may include solutions andsolids in powder form, which may be in combination with apharmaceutically acceptable carrier, such as an inert compressed gas,e.g. nitrogen.

Also included are solid form preparations that are intended to beconverted, shortly before use, to liquid form preparations for eitheroral or parenteral administration. Such liquid forms include solutions,suspensions and emulsions.

The compounds of the invention may also be deliverable transdermally.The transdermal compositions can take the form of creams, lotions,aerosols and/or emulsions and can be included in a transdermal patch ofthe matrix or reservoir type as are conventional in the art for thispurpose.

The compounds of this invention may also be delivered subcutaneously.

Preferably the compound is administered orally.

Preferably, the pharmaceutical preparation is in a unit dosage form. Insuch form, the preparation is subdivided into suitably sized unit dosescontaining appropriate quantities of the active component, e.g., aneffective amount to achieve the desired purpose.

The quantity of active compound in a unit dose of preparation may bevaried or adjusted from about 1 mg to about 100 mg, preferably fromabout 1 mg to about 50 mg, more preferably from about 1 mg to about 25mg, according to the particular application.

The actual dosage employed may be varied depending upon the requirementsof the patient and the severity of the condition being treated.Determination of the proper dosage regimen for a particular situation iswithin the skill of the art. For convenience, the total daily dosage maybe divided and administered in portions during the day as required.

The amount and frequency of administration of the compounds of theinvention and/or the pharmaceutically acceptable salts thereof will beregulated according to the judgment of the attending clinicianconsidering such factors as age, condition and size of the patient aswell as severity of the symptoms being treated. A typical recommendeddaily dosage regimen for oral administration can range from about 1mg/day to about 500 mg/day, preferably 1 mg/day to 200 mg/day, in two tofour divided doses.

Another aspect of this invention is a kit comprising a therapeuticallyeffective amount of at least one compound of Formula III, or apharmaceutically acceptable salt or solvate of said compound and apharmaceutically acceptable carrier, vehicle or diluent.

Yet another aspect of this invention is a kit comprising an amount of atleast one compound of Formula III, or a pharmaceutically acceptable saltor solvate of said compound and an amount of at least one anticancertherapy and/or anti-cancer agent listed above, wherein the amounts ofthe two or more ingredients result in desired therapeutic effect.

The invention disclosed herein is exemplified by the followingpreparations and examples which should not be construed to limit thescope of the disclosure. Alternative mechanistic pathways and analogousstructures will be apparent to those skilled in the art.

Where NMR data are presented, ¹H spectra were obtained on either aVarian VXR-200 (200 MHz, 1H), Varian Gemini-300 (300 MHz) or XL-400 (400MHz) and are reported as ppm down field from Me₄Si with number ofprotons, multiplicities, and coupling constants in Hertz indicatedparenthetically. Where LC/MS data are presented, analyses was performedusing an Applied Biosystems API-100 mass spectrometer and ShimadzuSCL-10A LC column: Altech platinum C18, 3 micron, 33 mm×7 mm ID;gradient flow: 0 min—10% CH₃CN, 5 min—95% CH₃CN, 7 min—95% CH₃CN, 7.5min—10% CH₃CN, 9 min—stop. The retention time and observed parent ionare given.

The following solvents and reagents may be referred to by theirabbreviations in parenthesis:

-   Thin layer chromatography: TLC-   dichloromethane: CH₂Cl₂-   ethyl acetate: AcOEt or EtOAc-   methanol: MeOH-   trifluoroacetate: TFA-   triethylamine: Et₃N or TEA-   butoxycarbonyl: n-Boc or Boc-   nuclear magnetic resonance spectroscopy: NMR-   liquid chromatography mass spectrometry: LCMS-   high resolution mass spectrometry: HRMS-   milliliters: mL-   millimoles: mmol-   microliters: μl-   grams: g-   milligrams: mg-   room temperature or rt (ambient): about 25° C.

EXAMPLES

For the preparation of compounds (R²=H; R⁴=halo, alkyl, trifluoromethyl,etc.) the known diaminopyridines (J. Med. Chem. 1997, 40, 3679) of TypeA are treated under cycloaddition conditions to afford the parentimidazo[1,2-a]pyridine skeletons B. Reductive amination with aldehydesyields compounds of Type C.

For more highly elaborated derivatives (R²=Br, Cl; R⁴=aryl orheteroaryl), the parent compound of Type B is treated under Suzukicoupling conditions to afford compounds of Type D. N-Acetylationfollowed by regioselective halogenation affords compounds of Type E. Theintermediate is elaborated via reductive amination to afford compoundsof Type F as described previously in Scheme 1.

N-acylated derivatives of Type G are treated under arylation conditionsfollowed by cleavage of the acetate under basic conditions to affordfinal products of type H.

Treatment of aniline core structures of Type C under standard acylationor sulfonylation conditions affords the final products I.

Nitrogen protection of aniline core I of Type I (R²=H, R⁴=Br) followedby palladium-mediated amination reaction affords the adduct J. In ananalogous fashion to Scheme 2, bromination followed by deprotection andreductive amination affords the adducts of type K.

Preparative Example 10

To a soln of bromoacetaldehyde diethyl acetal (2.37 mL, 15.4 mmol) indioxane/H₂O (2:1/15 mL) at rt was added conc. HCl (0.3 mL) and themixture was refluxed for 30 min. The mixture was cooled to rt whereuponNaHCO₃ (2.6 g, 30.8 mmol) was carefully added followed by dropwiseaddition of diamino derivative (1.5 g, 7.7 mmol) in dioxane/H₂O (2:1/15mL). The resultant mixture was stirred at reflux for 14 h and was cooledto rt. The mixture was diluted with 1 M NaOH (30 mL) and was extractedwith CH₂Cl₂ (3×35 mL). The organic layers were combined, washed withbrine (1×20 mL), dried (Na₂SO₄), filtered and concentrated under reducedpressure to afford 1.5 g (92%) of the desired compound [M+H=214.0].

Preparative Examples 11, 12

Following the procedure set forth in Preparative Example 10 but byutilizing known diaminopyridines (J. Med. Chem. 1997, 40, 3679), thefollowing imidazo[1,5-a]pyridine cores (Products) were prepared asindicated in Table 2.

TABLE 2 Pre- 1. Yield parative (%) Example Pyridine Product 2. MH⁺ 11

1. 732. 168.0 12

1. 842. 148.0

Example 20

To a solution of aniline (0.10 g, 0.47 mmol) from Preparative Example 10in MeOH (3 mL) at rt was added 4-pyridinecarboxyaldehyde (55 μL, 0.59mmol) and ZnCl₂ (112 mg, 0.82 mmol). The resultant mixture was stirredfor 1 h whereupon NaCNBH₃ (37 mg, 0.59 mmol) was added in one portion.The mixture was stirred at reflux for 14 h, cooled to rt, andconcentrated under reduced pressure. The crude material was partitionedbetween CH₂Cl₂ (7 mL) and 2M NaOH (3 mL) and the layers were separated.The aqueous layer was extracted with CH₂Cl₂ (2×7 mL) and the organiclayers were combined. The organic layer was dried (Na₂SO₄), filtered andconcentrated under reduced pressure. The crude material was purified byprep TLC (6×1000 μM) using CH₂Cl₂/MeOH (20:1) as eluant to afford 52 mg(37%) of a red-brown solid [M+H=305.0]; mp 167-172° C.

Examples 21-26

Following the procedure set forth in Example 20 but using the preparedaniline derivatives (Preparative Examples 11 & 12) indicated in Table 3and commercially available aldehydes, the substitutedimidazo[1,2-a]pyridine adducts were prepared (Products).

TABLE 3 1. Yield (%) Prep Ex. 2. MH⁺ Ex. Aniline Aldehyde Product 3. mp(° C.) 21 11

1. 732. 238.03. 135-137 22 11

1. 572. 239.03. 131-133 23 11

1. 682. 239.03. 131-133 24 12

1. 952. 258.13. 119-122 25 12

1. 352. 259.03. 125-127 26 12

1. 552. 259.03. 127-130

Preparative Example 20

To a solution of bromo compound from Preparative Example 10 (1.0 g, 4.72mmol) in DME/H₂O (4:1; 25 ml total) at rt was added PhB(OH)₂ (1.2 g, 9.4mmol), K₃PO₄ (3.0 g, 14.2 mmol), and Pd(PPh₃)₄ (0.54 g, 0.47 mmol). Themixture was heated at reflux for 18 h and was cooled to rt. EtOAc (30mL) and water (10 mL) were added and the layers were separated. Theaqueous layer was extracted with EtOAc (3×30 mL) and the organic layerswere combined. The organic layer was washed with brine (1×25 mL), dried(Na₂SO₄), filtered, and concentrated under reduced pressure to afford abrown oil. The crude product was purified by prep TLC (10×1000 μM) usingCH₂Cl₂/MeOH (25:1) as eluant to afford 0.9 g (91%) of a brown solid[M+H=209.0].

Preparative Examples 21-25

Following the procedure set forth in Preparative Example 20 but byutilizing different boronic acid in the Suzuki coupling reaction withaniline from Preparative Example 10, the following aniline cores(Products) were prepared as indicated in Table 4.

TABLE 4 Preparative Boronic 1. Yield (%) Example Acid Product 2. MH⁺ 21

1. 782. 244.0 22

1. 652. 278.0 23

1. 872. 244.0 24

1. 862. 278.0 25

1. 152. 250.0

Preparative Example 30

To a solution of aniline from Preparative Example 20 (0.12 g, 0.59 mmol)in CH₂Cl₂ (3 mL) at 0° C. was added pyridine (72 μL, 0.89 mmol) followedby dropwise addition of AcCl (50 μL, 0.71 mmol). The resultingheterogeneous mixture was stirred for 2 h at 0° C. and was concentratedunder reduced pressure. The crude residue was suspended in CH₂Cl₂ (10mL) and sat. aq. NaHCO₃ (5 mL) and the layers were separated. Theaqueous layer was extracted with CH₂Cl₂ (2×10 mL) and the organic layerswere combined. The organic layer was washed with brine (1×7 mL), dried(Na₂SO₄), filtered and concentrated under reduced pressure. The crudeproduct was purified by prep TLC (4×1000 μM) using CH₂Cl₂/MeOH (25:1) aseluant to afford 0.12 g (78% yield) of a yellowish solid [M+H=252.0].

Preparative Examples 31-36

Following the procedure set forth in Preparative Example 30 but byutilizing the following aniline cores described in Preparative Examples10, 21-25, the acylated derivatives (Products) were prepared asindicated in Table 5.

TABLE 5 Pre- para- tive Ex- Ani- 1. Yield (%) ample line Product 2. MH⁺31 Prep Ex.21

1. 952. 286.0 32 Prep Ex.22

1. 982. 320.1 33 Prep Ex.23

1. 932. 286.0 34 Prep Ex.24

1. 892. 320.1 35 Prep Ex.25

1. 762. 292.0 36 Prep Ex.10

1. 892. 256.0

Preparative Example 40

To a solution of acetate from Preparative Example 30 (0.12 g, 0.46 mmol)in CH₃CN (5 mL) at 0° C. was added NBS (73 mg, 0.41 mmol) in one portionto afford a heterogeneous mixture. The resulting solution was stirredfor 1 h at 0° C. whereupon the reaction mixture was concentrated underreduced pressure. The crude material was purified by prep TLC (6×1000μM) using CH₂Cl₂/MeOH (20:1) as eluant to afford 0.14 g (89%) of ayellow solid [M+H=330.1].

Preparative Examples 41-45

Following the procedure set forth in Preparative Example 40 but byutilizing the following aniline cores described in Preparative Examples31-34, the 3-bromo derivatives (Products) were prepared as indicated inTable 6.

TABLE 6 Preparative 1. Yield (%) Example Acetate Product 2. MH⁺ 41 PrepEx. 31

1. 792. 366.1 42 Prep Ex. 32

1. 722. 400.1 43 Prep Ex. 33

1. 762. 366.1 44 Prep Ex. 34

1. 892. 400.1 45 Prep Ex. 35

1. 982. 370.6

Preparative Example 50

To a solution of 3-bromo derivative from Preparative Example 40 (0.14 g,0.41 mmol) in EtOH (3 mL) was added conc. HCl (0.2 mL) and the mixturewas refluxed for 4 h. The mixture was cooled to rt and was concentratedunder reduced pressure. The crude product was partitioned between CH₂Cl₂(7 mL) and sat. aq. NaHCO₃ (3 mL) and the layers were separated. Theaqueous layer was extracted with CH₂Cl₂ (2×7 mL) and the organic layerswere combined. The organic layer was dried (Na₂SO₄), filtered andconcentrated under reduced pressure to afford 0.11 g (93% yield) of anoff-white solid [M+H=288.0]. This material was carried on withoutfurther purification.

Preparative Examples 51-54

Following the procedure set forth in Preparative Example 50 but byutilizing the following 3-bromo acetylated aniline cores described inPreparative Examples 41-44, the aniline derivatives (Products) wereprepared as indicated in Table 7.

TABLE 7 Preparative 3-Bromo 1. Yield (%) Example Derivative Product 2.M + H 51 Prep Ex.41

1. 882. 322.1 52 Prep Ex.42

1. 912. 358.1 53 Prep Ex.43

1. 992. 324.1 54 Prep Ex.44

1. 942. 356.1

Example 100

To a solution of aniline (0.11 g, 0.36 mmol) from Preparative Example 50in MeOH (4 mL) at rt was added 4-pyridinecarboxyaldehyde (44 μL, 0.46mmol) and ZnCl₂ (87 mg, 0.64 mmol). The resultant mixture was stirredfor 1 h whereupon NaCNBH₃ (29 mg, 0.46 mmol) was added in one portion.The mixture was stirred at reflux for 14 h, cooled to rt, andconcentrated under reduced pressure. The crude material was partitionedbetween CH₂Cl₂ (7 mL) and 2M NaOH (3 mL) and the layers were separated.The aqueous layer was extracted with CH₂Cl₂ (2×7 mL) and the organiclayers were combined. The organic layer was dried (Na₂SO₄), filtered andconcentrated under reduced pressure. The crude material was purified byprep TLC (6×1000 μM) using CH₂Cl₂/MeOH (20:1) as eluant to afford 0.07 g(49%) of a brown solid [M+H=379.1]; mp 167-172° C.

Examples 101-118

Following the procedure set forth in Example 100 but using the preparedaniline derivatives (Preparative Example 50-54) indicated in Table 8 andcommercially available aldehydes, the substituted imidazo[1,2-a]pyridineadducts were prepared (Products).

TABLE 8 1. Yield (%) Prep Ex. 2. M + H Ex. Aniline Aldehyde Product 3.mp (° C.) 101 50

1. 842. 379.13. 190-192 102 50

1. 852. 380.13. 160-162 103 50

1. 882. 386.13. 186-189 104 50

1. 892. 370.13. 179-181 105 50

1. 532. 382.13. 157-159 106 50

1. 352. 495.13. 198-200 107 50

1. 692. 431.13. 222-225 108 51

1. 472. 415.13. 199-201 109 51

1. 872. 415.13. 196-199 109 51

1. 432. 416.13. 206-208 111 51

1. 402. 431.13. 211-213 112 51

1. 902. 421.13. 200-202 113 52

1. 602. 449.13. 194-196 114 52

1. 952. 447.03. 192-195 115 53

1. 832. 415.13. 188-190 116 53

1. 422. 413.03. 191-194 117 54

1. 442. 449.1 118 54

1. 822. 449.13. 188-190 119 55

1. 362. 4213. 125-127 120 55

1. 222. 4223. 118-121 121 51

1. 832. 4833. 106-108 122 51

1. 792. 4923. 188-191 123 51

1. 982. 4543. 197-200 124 51

1. 222. 5613. 211-213

Preparative Example 60

To a solution of acetate (100 mg, 0.39 mmol) from Preparative Example 36in CH₃CN (4 mL) at 0° C. was added NCS (47 mg, 0.35 mmol) in oneportion. The mixture was warmed to rt and heated to reflux and stirredfor 1 h. The mixture was cooled to rt and was concentrated under reducedpressure. The crude material was purified by prep TLC (6×1000 μM) usingCH₂Cl₂/MeOH (22:1) as eluent to afford 96 mg (86%) of a white solid[M+H=290.0].

Preparative Example 65

Following the procedure set forth in Preparative Example 20 but byutilizing the acetate derivative from Preparative Example 60, the finaltarget was prepared in 79% yield as and orange solid [M+H=286.0].

Preparative Example 70

Following the procedure set forth in Preparative Example 50 but byutilizing the acetate derivative from Preparative Example 65, the finaltarget was prepared in 98% yield. [M+H=244.0].

Example 200

Following the procedure set forth in Example 100 except using theprepared aniline from Preparative Example 70 with4-pyridylcarboxaldehyde, the final product indicated in Table 9 andcommercially available aldehydes, the substituted imidazo[1,2-a]pyridineadduct was prepared as a light yellow solid in 35% yield. mp 202-205°C.; [M+H=335.0].

Preparative Example 80

To solution of acetate (30 mg, 0.09 mmol) from Preparative Example 40 inCH₂Cl₂ (2 mL) at rt was added Cu(OAc)₂ (16 mg, 0.09 mmol), PhB(OH)₂ (22mg, 0.18 mmol) and Et₃N (25 μL, 0.18 mmol). The mixture was stirred for24 h at rt and was concentrated under reduced pressure. The crudematerial was purified by prep TLC (4×1000 μM) using CH₂Cl₂/MeOH (25:1)as eluant to afford 15 mg (41%) of product [M+H=408.1].

Preparative Examples 81-82

Following the procedure set forth in Preparative Example 80 but byutilizing the specified acetylated aniline cores described inPreparative Examples 43,44 the aniline derivatives (Products) wereprepared as indicated in Table 10.

TABLE 10 Preparative 1. Yield (%) Example Acetate Product 2. MH⁺ 81 PrepEx.43

1. 212. 442.1 82 Prep Ex.44

1. 322. 474.1

Example 200

To a solution of the acetate (15 mg, 0.037 mmol) in MeOH/H₂O (1:1; 2 mLtotal) at rt was added KOH (42 mg, 0.74 mmol) in one portion. Themixture was stirred at reflux for 8 h, cooled to rt, and concentrated todryness. The resultant residue was partitioned between H₂O (1 mL) andCH₂Cl₂ (3 mL) and the layers were separated. The aqueous layer wasextracted with CH₂Cl₂ (2×3 mL) and the organic layers were combined. Theorganic layer was dried (Na₂SO₄), filtered, and concentrated underreduced pressure. The crude material was purified by prep TLC (4×1000μM) using hexanes/EtOAc (5:1) as eluant to afford 9 mg (67%) ofred-brown semisolid. [M+H=366.1].

Example 201

Following the procedure set forth in Example 200 but using the preparedacetate derivative (Preparative Example 50) indicated in Table 11available, the N8 phenyl substituted imidazo[1,2-a]pyridine adducts wereprepared (Products).

TABLE 11 Prep 1. Yield (%) Ex. 2. MH⁺ Ex. Aniline Product 3. mp (° C.)201 82

1. 782. 434.13. 152-153

Example 300

Following the procedure set forth in Example 30 except using theprepared aniline from Preparative Example 50, the acylated derivativewas prepared in 89% yield as a yellow solid, mp. 92-96° C.; [M+H=332.1].

Examples 301-304

Following the procedure set forth in Example 300 but using variousaniline cores as indicated in Table 12 reacting with designated acidchlorides, the N8 acylated substituted imidazo[1,2-a]pyridine adductsare prepared (Products).

TABLE 12 Prep Ex. Acid Ex. Aniline Chloride Product 301

302

303

304

Example 400

The core aniline from Preparative Example 50 is reacted withmethanesulfonyl chloride in the presence of pyridine to afford thedesired product.

Examples 401-404

Following the procedure set forth in Example 400 but using variousaniline cores as indicated in Table 13 reacting with designated acidchlorides, the N8 sulfonylated substituted imidazo[1,2-a]pyridineadducts are prepared (Products).

TABLE 13 Prep Ex. Sulfonyl Ex. Aniline Chloride Product 401

402

403

404

Preparative Example 90

Step A:

Treatment of aniline derivative from Preparative Example 10 understandard conditions (Boc₂O, Et₃N, DMAP) affords the correspondingcarbamate derivative.

Step B:

Treatment of the derivative from Step A under standard aminationconditions (Pd(OAc)₂, BINAP, Cs₂CO₃) and by employing cyclopentylamineaffords the desired cyclopentyl amine derivative.

Preparative Examples 91-100

Following the procedure set forth in Preparative Example 90 but byutilizing the carbamate described in Preparative Examples 90 Step A withvarious amines, the amino derivatives (Products) are prepared asindicated in Table 14.

TABLE 14 Prepa- rative Exam- ple Amine Product 91

92

93

94

95

96

97

98

99

100 

Preparative Example 101

Step A:

Treatment of Boc derivative from Preparative Example 90 according to theprocedure set forth in Preparative Example 40 affords the 3-bromoadduct.

Step B:

Treatment of the product from STEP A under acidic conditions (HCl)according to the procedure set forth in Preparative Example 50 affordsthe aniline derivative.

Preparative Examples 102-111

Following the procedure set forth in Preparative Example 100 but byutilizing the carbamate derivatives described in Preparative Examples91-95, the amino derivatives (Products) are prepared as indicated inTable 15.

TABLE 15 Preparative Example Carbamate Product 102 91

103 92

104 93

105 94

106 95

107 96

108 97

109 98

110 99

111 100

Example 500

Treatment of aniline from Preparative Example 100 with 3-pyridinecarboxaldehyde according to the procedure outlined in Example 100affords the title compound.

Examples 501-510

Following the procedure set forth in Example 500 but by utilizing theaniline derivatives described in Preparative Examples 101-105, the finaladducts (Products) can be prepared as indicated in Table 16.

TABLE 16 Aniline Example (Prep. Ex.) Product 501 102

502 103

503 104

504 105

505 106

506 107

507 108

508 109

509 110

510 111

Assay:

BACULOVIRUS CONSTRUCTIONS: Cyclin E was cloned into pVL1393 (Pharmingen,La Jolla, Calif.) by PCR, with the addition of 5 histidine residues atthe amino-terminal end to allow purification on nickel resin. Theexpressed protein was approximately 45 kDa. CDK2 was cloned into pVL1393by PCR, with the addition of a haemaglutinin epitope tag at thecarboxy-terminal end (YDVPDYAS). The expressed protein was approximately34 kDa in size.

ENZYME PRODUCTION: Recombinant baculoviruses expressing cyclin E andCDK2 were co-infected into SF9 cells at an equal multiplicity ofinfection (MOI=5), for 48 hrs. Cells were harvested by centrifugation at1000 RPM for 10 minutes, then pellets lysed on ice for 30 minutes infive times the pellet volume of lysis buffer containing 50 mM Tris pH8.0, 150 mM NaCl, 1% NP40, 1 mM DTT and protease inhibitors (RocheDiagnostics GmbH, Mannheim, Germany). Lysates were spun down at 15000RPM for 10 minutes and the supernatant retained. 5 ml of nickel beads(for one liter of SF9 cells) were washed three times in lysis buffer(Qiagen GmbH, Germany). Imidazole was added to the baculovirussupernatant to a final concentration of 20 mM, then incubated with thenickel beads for 45 minutes at 4° C. Proteins were eluted with lysisbuffer containing 250 mM imidazole. Eluate was dialyzed overnight in 2liters of kinase buffer containing 50 mM Tris pH 8.0, 1 mM DTT, 10 mMMgCl2, 100 uM sodium orthovanadate and 20% glycerol. Enzyme was storedin aliquots at −70° C.

IN VITRO KINASE ASSAY: Cyclin E/CDK2 kinase assays were performed in lowprotein binding 96-well plates (Corning Inc, Corning, N.Y.). Enzyme wasdiluted to a final concentration of 50 μg/ml in kinase buffer containing50 mM Tris pH 8.0, 10 mM MgCl₂, mM DTT, and 0.1 mM sodium orthovanadate.The substrate used in these reactions was a biotinylated peptide derivedfrom Histone H1 (from Amersham, UK). The substrate was thawed on ice anddiluted to 2 μM in kinase buffer. Compounds were diluted in 10% DMSO todesirable concentrations. For each kinase reaction, 20 μl of the 50μg/ml enzyme solution (1 μg of enzyme) and 20 μl of the 2 μM substratesolution were mixed, then combined with 10 μl of diluted compound ineach well for testing. The kinase reaction was started by addition of 50μl of 2 μM ATP and 0.1 μCi of ³³P-ATP (from Amersham, UK). The reactionwas allowed to run for 1 hour at room temperature. The reaction wasstopped by adding 200 μl of stop buffer containing 0.1% Triton X-100, 1mM ATP, 5 mM EDTA, and 5 mg/ml streptavidine coated SPA beads (fromAmersham, UK) for 15 minutes. The SPA beads were then captured onto a96-well GF/B filter plate (Packard/Perkin Elmer Life Sciences) using aFiltermate universal harvester (Packard/Perkin Elmer Life Sciences.).Non-specific signals were eliminated by washing the beads twice with 2MNaCl then twice with 2 M NaCl with 1% phosphoric acid. The radioactivesignal was then measured using a TopCount 96 well liquid scintillationcounter (from Packard/Perkin Elmer Life Sciences).

IC₅₀ DETERMINATION: Dose-response curves were plotted from inhibitiondata generated, each in duplicate, from 8 point serial dilutions ofinhibitory compounds. Concentration of compound was plotted against %kinase activity, calculated by CPM of treated samples divided by CPM ofuntreated samples. To generate IC₅₀ values, the dose-response curveswere then fitted to a standard sigmoidal curve and IC₅₀ values werederived by nonlinear regression analysis. The thus-obtained IC₅₀ valuesfor some representative compounds of the invention are shown in Table17.

TABLE 17 Examples CDK2 IC₅₀ (μM)

0.12

0.036

0.076

As demonstrated above by the assay values, the compounds of the presentinvention exhibit excellent CDK inhibitory properties.

While the present invention has been described with in conjunction withthe specific embodiments set forth above, many alternatives,modifications and other variations thereof will be apparent to those ofordinary skill in the art. All such alternatives, modifications andvariations are intended to fall within the spirit and scope of thepresent invention.

1. A method of inhibiting cyclin dependent kinase (“CDK2”), comprisingadministering a therapeutically effective amount of at least onecompound to a patient or a pharmaceutically acceptable salt of thecompound, said compound being selected from the group consisting of thefollowing compounds:


2. The method of claim 1, further comprising radiation therapy.
 3. Apharmaceutical composition comprising a therapeutically effective amountof at least one compound in combination with at least onepharmaceutically acceptable carrier, additionally comprising one or moreanti-cancer agents selected from the group consisting of a cytostaticagent, cisplatin, doxorubicin, taxotere, taxol, etoposide, CPT-11,irinotecan, camptostar, topotecan, paclitaxel, docetaxel, epothilones,tamoxifen, 5-fluorouracil, methoxtrexate, 5FU, temozolomide,cyclophosphamide, SCH 66336, R115777, L778,123, BMS 214662, Iressa,Tarceva, antibodies to EGFR, Gleevec, intron, ara-C, adriamycin,cytoxan, gemcitabine, Uracil mustard, Chlormethine, Ifosfamide,Melphalan, Chlorambucil, Pipobroman, Triethylenemelamine,Triethylenethiophosphoramine, Busulfan, Carmustine, Lomustine,Streptozocin, Dacarbazine, Floxuridine, Cytarabine, 6-Mercaptopurine,6-Thioguanine, Fludarabine phosphate, Pentostatine, Vinblastine,Vincristine, Vindesine, Bleomycin, Dactinomycin, Daunorubicin,Doxorubicin, Epirubicin, Idarubicin, Mithramycin, Deoxycoformycin,Mitomycin-C, L-Asparaginase, Teniposide 17α-Ethinylestradiol,Diethyistilbestrol, Testosterone, Prednisone, Fluoxymesterone,Dromostanolone propionate, Testolactone, Megestrolacetate,Methylprednisolone, Methyltestosterone, Prednisolone, Triamcinolone,Chlorotrianisene, Hydroxyprogesterone, Aminoglutethimide, Estramustine,Medroxyprogesteroneacetate, Leuprolide, Flutamide, Toremifene,goserelin, Cisplatin, Carboplatin, Hydroxyurea, Amsacrine, Procarbazine,Mitotane, Mitoxantrone, Levamisole, Navelbene, CPT-11, Anastrazole,Letrazole, Capecitabine, Reloxafine, Droloxafine, or Hexamethylmelamine,wherein said at least one compound is selected from the group consistingof the compounds of the structures: